


A Reasonable Conclusion

by Inell



Series: 2017 Prompt Challenge [49]
Category: Teen Wolf (TV)
Genre: Canon Compliant, Established Lydia Martin/Stiles Stilinski, F/M, Falling In Love, Fluff, Future Fic, M/M, Multi, Polyamory Negotiations, Post-Canon, Romance
Language: English
Status: Completed
Published: 2017-02-17
Updated: 2017-02-17
Packaged: 2018-09-25 05:24:12
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,238
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9804398
Author URL: https://archiveofourown.org/users/Inell/pseuds/Inell
Summary: Lydia has done her research and analyzed their current situation for months. She’s now come to a reasonable conclusion, and it’s time to share her findings with Stiles and Derek.





	

**Author's Note:**

> gingerqueen-lydiascream Prompt 2: Derek/Stiles/Lydia bringing a third person in
> 
> I know this is the triad that you wanted the most, so I decided to write it for you. I hope you enjoy it, bb! Fic #49 in my 2017 Prompt Challenge

 

“It isn’t like this would be a hardship for me, you know?” Lydia studies Stiles intently, and he squirms in his chair because he’s not entirely sure what she’s seeing in his expression.

“It wouldn’t?” Stiles drags his fingers through his hair. “I mean, it doesn’t matter, does it? You’re still suggesting this to make _me_ happy, and that’s not how relationships work. It’s not just about me. Same way it isn’t just about you, either.”

“Stiles, when have I ever been someone who makes impulsive decisions?” She arches a brow, her lips quirking into a fond smile. “I don’t. I’ve thought about this for weeks, possibly months if we’re being completely honest, and I’ve done my pro/con lists. I’ve done research and tested my theories and even completed a couple of flowcharts to ensure that the decision I made is the best possible one for not only the two of us but also Derek.”

“And you didn’t think about including _me_ in your analysis?” Stiles bites his lip. “It would have helped if I’d had any idea you were even considering suggesting something like this, Lydia.”

“No, it wouldn’t have done anything except make you anxious and awkward around Derek.” Lydia leans across the sofa and presses a kiss against the corner of his mouth. “Just like you are now. I mean, you’re working yourself into a tizzy for no reason. All that truly matters is the answer to one simple question: do you want this, Stiles?”

“That’s not a simple question at all!” Stiles tugs on his hair and avoids looking at her for a moment as he tries to get his thoughts and emotions under control. “It’s incredibly complicated, and you know it.”

“What I know is that you’re attracted to Derek, and he’s attracted to you. There’s always been _something_ between you two, but you were too young, and he was too fucked up to ever give it a go. Then he left, and I got my head out of my ass and realized that my feelings for you went far beyond just friendship, so I was able to benefit from that something never becoming anything.” Lydia looks so earnest as she’s talking that Stiles can’t help but listen and focus on her words instead of freaking out and feeling guilty.

“I was a Nice Guy™ Creepoid to you for years, and I put you on this pedestal without really treating you like an actual person, so it’s little wonder that you didn’t realize what I catch I am sooner because, well, I wasn’t actually that great back then,” he points out. “I was really obnoxious, in fact, and I still don’t know how you can forgive me for being such a gross guy but I’m not going to question my good fortune.”

“You _were_ awful,” she agrees. “But you changed and grew up, and so did I. It’s not like I was any catch back then, either. My entire mission in life was to rule the school and play the part of brainless queen bitch. If anything, you at least saw through some of that image to realize what I was hiding.” She shrugs a delicate shoulder, and he can’t help but reach out to drag the strap of her tank top back up from where it’s slid down. “That was all years ago, Stiles. We’ve shown that we can persevere through long-distance relationships and grad school and jobs requiring travel, so we know we’re strong enough to get through anything.”

“Well, you know that the only reason we survived long-distance was because we decided to break-up before college,” he says, stroking his fingers along the column of her neck. “If we hadn’t had that break to stumble and learn we who are outside of Beacon Hills, I don’t know if we’d be here now.”

“That’s true.” Lydia leans into his touch, probably dealing with the same memories he had of that year apart, when he'd tumbled into the whole freshman year nonsense as a single guy. She smiles at him. “Regardless, we _did_ make it, and my point stands that we're stronger now than ever before. I mean, we're only twenty-eight, and we have a nice apartment in Portland, jobs we both really love, and a relationship that's the envy of most our friends. Besides that, I finally realized _why_ Peter Hale pointed Barton in my direction after you got transferred.”

“Wait. _Peter_ is the one who got you the hook up with Bartech?” Stiles blinks at her. “Why am I just now hearing about this? Does he realize you know?”

“Because it isn’t important who referred me to Barton since I earned the position on my own,” she says. “No, I'm sure he has no idea that I realize he's the one who gave my name to the company. I also didn't mention anything to you because I hadn’t really figured out Peter’s intent until Derek just happened to cross our paths again, and I saw the way he looked at you, like you were the moon shining bright after years of utter darkness.”

“You’re getting lyrical, Lyds.” Stiles ducks his head because, well, he can’t deny the way Derek looks at him sometimes. They’ve been in Portland for nearly two years now, and Derek showed up in their lives about six months later. In that time, they’ve become friends, the three of them often hanging out and doing things together. And when he’s got an assignment outside of Portland with his team, he knows that Lydia and Derek hang out, the same way he and Derek do when Lydia’s presenting research at some conference or another.

“Perhaps love makes my lyrical,” she muses, pursing her lips as she seems to analyze the thought. “No, it doesn’t. That’s the only appropriate way to describe that look. Stiles, our relationship is successful because we’re always honest with each other, and we make sure that we communicate so that we don’t misunderstand anything. Tell me right now, honestly, that you wouldn’t be dating Derek if you were single.”

“I can’t do that,” he whispers, letting his hand drop from her neck so he can take her hand in his. “But I’m _not_ single. I love you. Being with you makes me happy. Hell, we’ve talked about marriage in a couple of years, maybe even kids eventually, once you’ve accomplished all of your career goals and I can travel less.”

“Stiles, I need you to listen to me, alright?” Lydia drags her fingers over the back of his hand and smiles sweetly. “If I weren’t involved with you, I’d want to date Derek. I know my relationship with him is newer, more of an intellectual common ground and a shared love for you, but I’m attracted to him, and I like being around him. I think he feels the same about both of us, which is why I made the suggestion that I have.”

“You would?” Stiles waits for the nagging insecurity to hit, but it doesn’t. No, he’s confident in his relationship with Lydia. They took a break and got back together because they just fit in a way that works really well for them. “So this isn’t really just something to try to appease me or make me not feel guilty for having an emotional connection with someone else?”

“Not at all. If it were anyone but Derek, I certainly wouldn’t be as understanding and open-minded, of course. However, I know that’s not an issue because I trust you completely, and we’re happy. If you were unhappy with something, you’d let me know. You wouldn’t cheat on me, ever, and I know you’d never even consider it with Derek regardless of the feelings you have for him.” Lydia leans forward to press their lips together in a soft kiss. “You and I have talked about the idea of polyamory before, back in college, and I think this is the right time to consider it again.”

“Do you think…is it something he might…” Stiles isn’t sure if Derek would even be interested in an offer to be their third. It’s not a lifestyle that just anyone can live, and he recognizes that it’s going to be complicated to try and settle into a dynamic with three personalities like theirs, but, God, he wishes it were possible. He loves Lydia so much, but she’s right. There’s always been a connection between him and Derek that’s the ‘what if’ of his life.

“We can ask him.” Lydia smiles slyly before she gets off the sofa. “He’s been listening outside the door since you were rambling apologies about emotionally cheating on me, which I understand _is_ a big deal for you and made you feel guilty, but isn’t something that bothers me, so you need to let it go and realize that I’m amazing, and you’re damn lucky to have me.”

“I already know all those things. I _am_ lucky to have you,” Stiles says, scrambling off the sofa. “How do you know he’s there?”

“Because I invited him over for a talk, of course.” She tosses her hair over her shoulder before she opens the door to their apartment. Derek is standing there looking stunned and slightly guilty, like he’s not sure if he should stay or run far away. “Hello, Derek. I apologize for the subterfuge, but I thought the only way you’d truly believe us is if you heard us discussing it candidly. Won’t you come in?”

“I, uh.” Derek stares at her then looks at Stiles. “Can I?”

“Yes. God yes.” Stiles steps forward. “I’m still reeling from all this, but you must be totally shocked.”

“I’m beginning to understand some of her cinematic choices a little more,” Derek admits, glancing at Lydia and giving her a small smile. “I guess I should have realized you were up to something when you made me watch Y Tu Mama Tambien, but I just thought you had a crush on that one actor.”

“Guilty as charged.” Lydia holds up her hands and smirks. “I was trying for subtlety to test the waters regarding your opinion on polyamory and pushing at some of your boundaries so that I could have accurate research for my analysis of our little problem here.”

“I can’t believe you watched sexy Spanish movies without me,” Stiles grumbles, sulking a bit when they look at him. “Was that when I was stuck in Seattle tracking the human trafficking ring? Because, if so, you both owe me _so much_. That was a miserable assignment with cold rain constantly, and I actually had moments of regretting my choice to become an agent during that case since it was underage homeless kids and, yeah.”

“We’ll make it up to you.” Stiles blinks because it’s not Lydia who spoke, but Derek. Derek who just now seems to realize what he’s said based on the fact that the tips of his ears are flushing a lovely shade of red and he’s suddenly finding the floor fascinating.

“Yes, _we_ will,” Lydia says, picking up the conversation with a wink at Stiles. She hooks her arm through Derek’s, squeezing his bicep gently before leading him over towards the couch and Stiles. “We should talk first, though.”

“Talking is good,” Stiles agrees, walking back and sitting down on the couch. Lydia pushes Derek onto it beside him before taking the space on the other side of Derek. “Can you handle talking, Derek?”

“Maybe.” Derek rubs his thighs with his fists before gripping his knees with both hands. “I don’t…I don’t want anything to mess up our friendships. Alright?”

“Whatever is discussed right now won’t affect our friendships at all,” Lydia promises. “We’re all adults, and we can be friends despite an attraction or feelings existing without those things affecting our platonic bond. I just happen to think, after several months of analysis, that the three of us could have a successful polyamorous triad and be even happier than we are now.”

“What exactly is that?” Derek looks up at Lydia then looks at Stiles. “I mean, I know triad means three, but I honestly don’t know much about polyamory beyond it being open relationships.”

“It’s different for everyone,” Stiles says, turning so that he’s sitting sideways on the couch and facing Derek. “Some people do an open relationship that is just sexual, and others do triads that are more permanent, and others do vees, and there are a lot of different possibilities. Lydia and I, when we talked about it before, we discussed possibly finding a third person that we both loved and wanted romantically that could become part of our lives. We’re not looking for casual sex or an unbalanced relationship. If you decide to do this, you’re getting both of us. Fully and completely.”

“You’d be dating both of us, having sex with both of us, hopefully living with us at some point, possibly making things more formal when we’re in our thirties and ready to do the legal paperwork,” Lydia adds. “But it wouldn’t always be the three of us. Sometimes, you and Stiles might have sex while I’m sleeping, or you and I might go on a date when Stiles is traveling for work, or Stiles and I might have a romantic evening while you watch those boring documentaries on History channel.”

“They aren’t boring,” Derek says, lips quirking slightly. “So, let me see if I understand all of this. I’d be dating and having sex with both of you, and you’d be doing that with me and each other. Can you actually do that without, like, being jealous? I can be a little possessive sometimes.” He shrugs and smiles wryly, like he’s admitting something they don’t know.

“Dude, you’re possessive as just our friend. I think we both know what we’re getting into if we make this romantic,” Stiles tells him. “It’s just a wolfy trait of yours that we can accept, like you’d have to accept that Lydia constantly steals the covers and that I wake up screaming sometimes because of nightmares.”

“I wouldn’t have to steal the covers if _someone_ wasn’t always stealing them first.” Lydia puts her hand on Derek’s thigh and leans over him to smile at Stiles. “I bet Derek won’t steal the covers from me.”

“You won’t even need covers if he’s sleeping in the middle. He’s so damn hot,” Stiles says, waggling his eyebrows as he leans over and kisses her. “In more ways than one.” He turns to look at Derek, seeing the way he’s staring at them and watching them kiss, and he can’t resist leaning in. “Is this okay, Derek? I’m not doing anything with your consent. Never gonna do that.”

“Yeah, it’s okay,” Derek whispers before he leans in and kisses Stiles. It’s their first kiss, obviously, and it’s a little awkward because of the angle, and they’re both trying to control it, and it’s a little messy and wet but then it just sort of snaps together.

Derek’s touching his face gently, and Stiles is gripping his hair, and they’re moving their lips and licking and nibbling and then he feels soft lips on the curve of his jaw, kissing a path from his ear forward. And then he’s pulling back and watching Lydia’s mouth press against Derek’s, waiting for any rush of jealous but not that surprised when there isn’t one because they’re both his, and he knows that. He _feels_ it in his gut. When Lydia and Derek stop kissing, Stiles leans in to lick at their mouths, teasing a little before pulling back. “So, uh, that was hot.”

“Understatement,” Lydia mutters, rolling her eyes even as her lips curve into the fond ‘I adore you’ smile that’s his favorite. “But we shouldn’t be letting our hormones interfere with this decision. Derek needs to be able to think without any undue influence from us.”

“I think Derek can speak for himself,” Derek says, his eyebrows arching and giving Lydia a run for her money with the judgmental brow thing. “And Derek—I mean, _I_ —know what my decision is, and I knew it before the kissing happened. In fact, the kissing just confirmed that I’d made the right choice.”

“Did it?” Stiles shifts so that he’s straddling Derek’s left leg. He watches Lydia smirk at him before doing the same to Derek’s right leg. He takes Lydia’s hand, squeezing it gently as he looks at Derek. “So, what’s it gonna be? Do you wanna be our third, Derek? Become part of our relationship, work on being the most awesome triad ever? In sickness and health. Richer or poorer. All that jazz.”

“Ignore him. There aren’t any vows necessary,” Lydia says, stroking her fingers across Stiles’ palm as she reaches up to brush Derek’s hair away from his forehead. “He just likes the sappy aspects of ceremonies, yet has the gall to call me lyrical.”

“I kinda like the vows,” Derek admits, winking at Stiles as he reaches over to stroke Stiles’ face. “And you _are_ lyrical when it comes to love, Lydia. I’ve heard you go hardcore poetic after a half bottle of wine when talking about Stiles’ eyes and his lips.”

“Oh really?” Stiles looks at Lydia and smirks. “I think I need to hear more about these poetic odes to my eyes and lips.”

“I think certain werewolves need to keep their mouths shut unless they want certain ‘golden eyed heartbreakers’ to hear their own non-wine induced odes,” Lydia warns, moving her fingers from Derek’s forehead down to caress his bearded jaw. “You still haven’t answered our question, Derek.”

“You’d better answer it soon. She’ll get impatient,” Stiles says, grinning at Derek as he moves his head and presses a kiss against Derek’s palm. “I mean, I think we both already kinda know your answer, but we need to hear you say it.”

“What’s the question again?” Derek deadpans, lips twitching before he grins widely, a breathtaking smile that makes his eyes crinkle, and he looks happier than Stiles has ever seen him, something that Lydia must see, too, because she squeezes his hand tight as Derek looks at them. “I don’t need any time to think about this, so don’t think I’m rushing in or taking this lightly. I’d love to be your third, though. It’s something I’ve thought about since we met again, but I didn’t know how to suggest it or if you’d want it or if it was selfish of me to want to you both to be mine.”

“Silly boy.” Lydia shakes her head. “Stiles has been yours for years, and I’ve been yours since that rainy walk to get ice cream.”

“Yeah. What she said,” Stiles says, leaning in to kiss Derek lightly. “But now you’re ours, too.”

“Who’s being silly now?” Derek asks, pulling Lydia in closer to them and kissing her before watching Stiles kiss her. When they pull back, Derek’s still smiling that gorgeous, breathtaking, happy smile as he touches their faces gently, like he’s unable to believe this is happening, which is a familiar feeling for Stiles at the moment but one that’ll soon fade to the reality that, yes, they are doing this, and yes, they’re going to be the most awesome triad in the history of polyamory. Derek leans in and presses his forehead against theirs as he whispers, “I’ve always been yours.”

**Author's Note:**

> [My Tumblr](http://inell.tumblr.com)


End file.
